An early wireless communication system has been developed to provide voice services while ensuring the mobility of users. In addition, the wireless communication system has been expanded from the voice service to a data service. In recent years, the wireless communication system has been developed to provide a high-speed data service.
FIG. 1 illustrates a configuration of a wireless communication system. Referring to FIG. 1, the wireless communication system may include a terminal (may be referred to as a User Equipment (UE)) 100, a Radio Access Network (RAN) 130 and a core network 140.
The RAN 130 may include a plurality of configuration elements. A configuration element 120 of the RAN interacting with the UE 100 may communicate with the UE 100 through a wireless interface 110. Remaining elements of the wireless communication system may be connected with each other by wires. For example, the RAN configuration element 120 interacting with the UE 100 through the wireless interface 110 may include a portion of an evolved Node B (eNB), a Node B (NB), a Radio Network Subsystem (RNS) including the NB, a Base Transceiver Station (BTS), a Base Station Subsystem (BSS) including the BTS, a wireless access point, a home eNB, a home NB, a home eNB GateWay (GW) and an X2 GW. In the present specification, for convenience, the RAN configuration element is referred to as at least one of the examples of the RAN configuration element 120 described above by using a term of radio access point, or is referred to as the RAN 130.
The radio access point 120 may include at least one cell. The cell controls a specific area, and the UE 100 receives a service in an area of the cell. Here, the cell means a cell of a cellular system, and the radio access point 120 means a device managing and controlling the cell. But, in the present specification, for convenience, the cell and the radio access point 120 may have the same meaning. The cell and the radio access point 120 may be mixed in describing one object (e.g. an exemplary embodiment), according to convenience.
The core network 140 may include a RAN control entity 135. The RAN control entity 135 takes charge of overall control functions such as a mobility management, an certification, a security, and the like. For example, the RAN control entity 135 may include a portion of a Mobility Management Entity (MME) and a Serving General Packet Radio Service (GPRS) Support Node (SGSN).
Because the radio access point 120 provides the service to the UE 100 through the wireless interface 110, each of the radio access points 120 has a coverage suitable for providing the service.